1. Field of Invention
The invention relates to a prism pole for supporting a reflective prism or other piece of equipment for surveying landforms, structures, etc, which facilitates automatically taking height measurements and providing height reference data corresponding therewith.
2. Description of Related Art
Prism poles as used in surveying to support a reflective prism or other piece of surveying equipment. Prior art prism poles, of the prior art, such as shown in FIG. 1, include a tubular housing and a height-adjustable rod partially inserted therein. The height-adjustable rod slides inwardly and outwardly with respect to the tubular housing. Prior art prism poles include a numerical scale printed on the height-adjustable rod, typically marked in increments of hundredths ( 1/100) of a foot or thousandths ( 1/1000) of a meter. A reflective prism or other piece of surveying equipment attaches to the top of the height-adjustable rod. A prism pole operator can manually read a height measurement from the numerical scale at a point along the height-adjustable rod. The operator typically then records the height measurement into a log book or manually enters the height measurement into a data collection device.
Prior art prism poles allow human error to interfere with accurate measurement-taking. For example, the height-adjustable rod of the prism pole may slowly slip down into the tubular housing, unbeknownst to the prism pole operator. Because the operator is unaware of minor slippage, the operator errs in recording accurate height measurements. Prior art prism poles are also problematic because operators often misread height measurements from the numerical scale. In addition, operators often fail to record changes in height measurements when the operator adjusts the position of the height-adjustable rod. Operators also make transposition errors when manually copying height measurements from the numerical scale into a log book or data collection device. A prism pole is needed that reduces the amount of human error that interferes with accurate measurement-taking.